华北地区地壳P波三维速度结构
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摘要
1968年邢台地震以后的30余年中,中国地震局系统先后在大华北地区布置30余条、近20000km的人工地震宽角反射/折射深地震测深(DSS)剖面,用以研究地壳及上地幔顶部的速度结构,取得了大量研究成果.但以往的研究明显的不足是未能形成华北区域性的地壳三维速度结构模型,从大区域的角度为研究华北地区地壳深部构造特征提供地震学方面的依据.因此,在现已发表的DSS剖面资料的基础上,选择了14条测线的资料,利用地理信息系统(ARC/INFO)的"矢量化"功能,以及克里格数据网格化技术构建华北区域性的地壳三维速度结构模型,从而对华北研究区内地壳三维速度结构的特点得到如下认识:(1)华北地区地壳表层P波速度变化幅度大,平面结构较复杂,大体上划分为相间排列、走向趋势以北西向为主的3个速度区.海河平原和渤海湾的低速带是研究区范围内速度最低的低速区.资料的情况说明,研究区内沉积盖层的地质构造与上地壳构造之间虽有一定继承性,但也存在较大差别.(2)总体上看,在华北研究区内地壳的P波速度随深度增大而增大,但局部地区出现速度倒转的现象,东区的海河平原低速异常逐渐消失,而西区的山西地堑则以相对低速异常特征为主.区内地壳以太行山脉为界,划分为东、西两区;东部和西部,结晶基底以上地层的构造方向不完全一致;东部的黄淮海地块,区域构造以北东向为主,而西部包括山西地块和鄂尔多斯地块东缘,其构造方向则以北西向为主.(3)根据莫霍面的形态特征,研究区地壳可大致划分为6个区块;在山西地块范围内,莫霍面呈近南北向的凹陷带,地壳厚度大;内蒙古地块南缘和燕山地块南部,莫霍面表现出褶皱带的构造特征,其延展趋势为近东西方向;鄂尔多斯地块东缘,莫霍面构造相对复杂,呈近北西向凸、凹相伴的褶皱;黄淮海地块(华北裂谷带中、北部)为莫霍面隆坳区,隆、坳相间排列,构造较复杂,但从整体上看,这是全区莫霍面最浅的隆起区段;鲁西台背斜主要为莫霍面断陷区,其断陷带沿枣庄—曲阜一线向北西方向延伸.
To research the velocity structure of crust and upper mantle, China Earthquake Administration has finished more than thirty deep seismic sounding (DSS)profiles, altogether about twenty thousand kilometers long in North China since the 1968 Xingtai earthquake. But these researches have not given out a 3D velocity structure model of the crust of North China and can not provide seismic evidence for researching deep structure features of the crust of North China. So based on the published research papers on DSS profiles, a 3D velocity structure model of North China is obtained by using vectorization function of GIS soft (Arc/Info) and Kriging regularization. With this velocity structure model, we have come to the following conclusions:(1) P-wave velocity of the shallow crust of North China changes rapidly, and the velocity structure is complex at the same depth. In general, it can be divided into three velocity zones, mainly tending to North West. In the research area, the lowest velocity zone is the Haihe plain and Bohai bay low-velocity zone. Geological structure of upper crust is inherited by deposit shell partially, but there are also lots of differences between them.(2) Generally, P-wave velocity increases with depth in the research zone, but it is inversed in local zones. Haihe plain low-velocity anomalous zone in the east disappeared, and Shanxi valley in the west is characterized by low velocity anomaly. The crust is divided into east part and west part by Taihang mountain. The strike of the strata above crystal floor is not completely consistent between the east part and the west one. The strike of Huanghai block and Huaihai block in the east mainly tends towards north-east, while the strike of Shanxi block and the eastern edge of Ordos block in the west mainly tends towards north-west.(3) According to the feature of Moho, the crust of the research zone can be divided into six parts: in the Shanxi block, Moho looks like a nearly north-south sunk belt, and the crust is thick; at the southern edge of the Inner Mongolia block and in the south of Yanshan block, Moho presents the structural features of fold belt, tending nearly towards east-west; at the eastern edge of Ordos block, the structure of Moho is relatively complex with nearly northwest folds.
To research the velocity structure of crust and upper mantle, China Earthquake Administration has finished more than thirty deep seismic sounding (DSS)profiles, altogether about twenty thousand kilometers long in North China since the 1968 Xingtai earthquake. But these researches have not given out a 3D velocity structure model of the crust of North China and can not provide seismic evidence for researching deep structure features of the crust of North China. So based on the published research papers on DSS profiles, a 3D velocity structure model of North China is obtained by using vectorization function of GIS soft (Arc/Info) and Kriging regularization. With this velocity structure model, we have come to the following conclusions:(1) P-wave velocity of the shallow crust of North China changes rapidly, and the velocity structure is complex at the same depth. In general, it can be divided into three velocity zones, mainly tending to North West. In the research area, the lowest velocity zone is the Haihe plain and Bohai bay low-velocity zone. Geological structure of upper crust is inherited by deposit shell partially, but there are also lots of differences between them.(2) Generally, P-wave velocity increases with depth in the research zone, but it is inversed in local zones. Haihe plain low-velocity anomalous zone in the east disappeared, and Shanxi valley in the west is characterized by low velocity anomaly. The crust is divided into east part and west part by Taihang mountain. The strike of the strata above crystal floor is not completely consistent between the east part and the west one. The strike of Huanghai block and Huaihai block in the east mainly tends towards north-east, while the strike of Shanxi block and the eastern edge of Ordos block in the west mainly tends towards north-west.(3) According to the feature of Moho, the crust of the research zone can be divided into six parts: in the Shanxi block, Moho looks like a nearly north-south sunk belt, and the crust is thick; at the southern edge of the Inner Mongolia block and in the south of Yanshan block, Moho presents the structural features of fold belt, tending nearly towards east-west; at the eastern edge of Ordos block, the structure of Moho is relatively complex with nearly northwest folds.
引文
Fan,H.,1999.The developmental technique and apply ofARC/INFO.Publishing House of University of Scienceand Technology of Surveying and Drawing in Wuhan,Wuhan,45-57(in Chinese).
Jia,S.X.,Liu,C.Q.,1991.Interpretation of Heze-ChangzhiDSS profile in south of the basinin North China.NorthChina Earthquake Sciences,9(2):11-20(in Chinesewith English abstract).
Liu,C.Q.,Fang,S.M.,Li,C.F.,1996.Joint gravity-seismicinterpretation for Yingxian-Zibo profile.Seismologyand Geology,18(4):369-374(in Chinese with Englishabstract).
Liu,C.Q,Jia,S.X.,Li,C.F.,et al.,1997.Deep structurebackground of1966XingtaiM=6.8earthquake.NorthChina Earthquake Sciences,15(2):17-23(in Chinesewith English abstract).
Ren,Q.F.,Zhang,C.K.,Zhao,J.R.,et al.,1992.Charac-teristics of crustal structures in Heze region and earth-quakes.North China Earthquake Sciences,10(3):45-52(in Chinese with English abstract).
Wang,C.Y.,Zhang,X.K.,Wu,Q.J.,et al.,1994.The seis-mological evidence of the slip structure in the basin inNorth China.Acta Geophysica Sinica,37(5):613-619(in Chinese with English abstract).
Wang,J.H.,Gao,H.Y.,Zhou,Y.,1999.Kriging geologicalmapping technique—Models and algorithms on comput-ers.PetroleumIndustry Press,Beijing,73-77(in Chi-nese).
Yuan,Z.X.,Ding,Y.Y.,Di,X.L.,1999.The crustal seismicS-wave velocity i mage in the Weihe sownfaulted basinand its adjacent areas.Seismology and Geology,21(1):9-16(in Chinese with English abstract).
Zhang,C.K.,Zhang,X.K.,Gai,Y.J.,et al.,1997.Astudyof crust and upper mantle structure on Wen′an-Yuxian-Qaharyouyizhongqi profile.North China EarthquakeSciences,15(3):18-28(in Chinese with English ab-stract).
Zhang,J.S.,Zhu,Z.P.,Zhang,X.K.,et al,1997.The seis-mic velocity structure of crust and upper mantle anddeep structure feature in North Shanxi plateau.Seis-mology and Geology,19(3):220-226(in Chinese withEnglish abstract).
Zhu,Z.P.,Zhang,J.S.,Zhang,C.K.,et al.,1999.Study onthe structure of the crust and mantle in Centre andSouth of Shanxi.Journal of Earthquake,21(1):42-49(in Chinese with English abstract).
Zhu,Z.P.,Zhang,J.S.,Zhou,X.S.,et al.,1994.Study onthe structure of the crust and upper mantle in Linfenearthquake region in Shanxi.North China EarthquakeSciences,12(1):77-83(in Chinese with English ab-stract).
Zhu,Z.P.,Zhang,X.K.,Gai,Y.J.,et al.,1995.Study onthe seismic velocity structure of the crust and uppermantle in Xingtai earthquake region and near area.Journal of Earthquake,17(3):328-334(in Chinesewith English abstract).
Zhu,Z.P.,Zhang,X.K.,Zhang,J.S.,et al.,1997.Study onthe seismic velocity structure of the crust and uppermantle on Beijing-Huailai-Fengzhen profile.Journal ofEarthquake,19(5):499-505(in Chinese with Englishabstract).
樊红,1999.ARC/INFO应用与开发技术.武汉:武汉测绘科技大学出版社,45-57.
嘉世旭,刘昌铨,1991.华北裂谷盆地南部菏泽-长治地震测深剖面结果解释.华北地震科学,9(2):11-20.
刘昌铨,方盛明,李长法,1996.应县-淄博剖面重力、地震测深联合解释.地震地质,18(4):369-374.
刘昌铨,嘉世旭,李长法,等,1997.1966年邢台6.8级地震的深部结构背景.华北地震科学,15(2):17-23.
任青芳,张成科,赵金仁,等,1992.菏泽地区地壳结构特征与地震.华北地震科学,10(3):45-52.
王椿镛,张先康,吴庆举,等,1994.华北盆地滑脱构造的地震学证据.地球物理学报,37(5):613-619.
王家华,高海余,周叶,1999.克里金地质绘图技术———计算机的模型和算法.北京:石油工业出版社,73-77.
袁志祥,丁韫玉,狄秀玲,1999.渭河断陷及邻近地区地壳S波速度图像.地震地质,21(1):9-16.
张成科,张先康,盖玉杰,等,1997.文安-蔚县-察右中旗剖面地壳上地幔速度结构与构造研究.华北地震科学,15(3):18-28.
张建狮,祝治平,张先康,等,1997.山西高原北部地壳上地幔地震波速结构与深部构造.地震地质,19(3):220-226.
祝治平,张建狮,张成科,等,1999.山西中南部壳幔结构的研究.地震学报,21(1):42-49.
祝治平,张建狮,周雪松,等,1994.山西临汾震区地壳上地幔构造的研究.华北地震科学,12(1):77-83.
祝治平,张先康,盖玉杰,等,1995.邢台震源区及相邻地区地壳上地幔速度结构研究.地震学报,17(3):328-334.
祝治平,张先康,张建狮,等,1997.北京-怀来-丰镇剖面地壳上地幔构造与速度结构研究.地震学报,19(5):499-505.
Jia,S.X.,Liu,C.Q.,1991.Interpretation of Heze-ChangzhiDSS profile in south of the basinin North China.NorthChina Earthquake Sciences,9(2):11-20(in Chinesewith English abstract).
Liu,C.Q.,Fang,S.M.,Li,C.F.,1996.Joint gravity-seismicinterpretation for Yingxian-Zibo profile.Seismologyand Geology,18(4):369-374(in Chinese with Englishabstract).
Liu,C.Q,Jia,S.X.,Li,C.F.,et al.,1997.Deep structurebackground of1966XingtaiM=6.8earthquake.NorthChina Earthquake Sciences,15(2):17-23(in Chinesewith English abstract).
Ren,Q.F.,Zhang,C.K.,Zhao,J.R.,et al.,1992.Charac-teristics of crustal structures in Heze region and earth-quakes.North China Earthquake Sciences,10(3):45-52(in Chinese with English abstract).
Wang,C.Y.,Zhang,X.K.,Wu,Q.J.,et al.,1994.The seis-mological evidence of the slip structure in the basin inNorth China.Acta Geophysica Sinica,37(5):613-619(in Chinese with English abstract).
Wang,J.H.,Gao,H.Y.,Zhou,Y.,1999.Kriging geologicalmapping technique—Models and algorithms on comput-ers.PetroleumIndustry Press,Beijing,73-77(in Chi-nese).
Yuan,Z.X.,Ding,Y.Y.,Di,X.L.,1999.The crustal seismicS-wave velocity i mage in the Weihe sownfaulted basinand its adjacent areas.Seismology and Geology,21(1):9-16(in Chinese with English abstract).
Zhang,C.K.,Zhang,X.K.,Gai,Y.J.,et al.,1997.Astudyof crust and upper mantle structure on Wen′an-Yuxian-Qaharyouyizhongqi profile.North China EarthquakeSciences,15(3):18-28(in Chinese with English ab-stract).
Zhang,J.S.,Zhu,Z.P.,Zhang,X.K.,et al,1997.The seis-mic velocity structure of crust and upper mantle anddeep structure feature in North Shanxi plateau.Seis-mology and Geology,19(3):220-226(in Chinese withEnglish abstract).
Zhu,Z.P.,Zhang,J.S.,Zhang,C.K.,et al.,1999.Study onthe structure of the crust and mantle in Centre andSouth of Shanxi.Journal of Earthquake,21(1):42-49(in Chinese with English abstract).
Zhu,Z.P.,Zhang,J.S.,Zhou,X.S.,et al.,1994.Study onthe structure of the crust and upper mantle in Linfenearthquake region in Shanxi.North China EarthquakeSciences,12(1):77-83(in Chinese with English ab-stract).
Zhu,Z.P.,Zhang,X.K.,Gai,Y.J.,et al.,1995.Study onthe seismic velocity structure of the crust and uppermantle in Xingtai earthquake region and near area.Journal of Earthquake,17(3):328-334(in Chinesewith English abstract).
Zhu,Z.P.,Zhang,X.K.,Zhang,J.S.,et al.,1997.Study onthe seismic velocity structure of the crust and uppermantle on Beijing-Huailai-Fengzhen profile.Journal ofEarthquake,19(5):499-505(in Chinese with Englishabstract).
樊红,1999.ARC/INFO应用与开发技术.武汉:武汉测绘科技大学出版社,45-57.
嘉世旭,刘昌铨,1991.华北裂谷盆地南部菏泽-长治地震测深剖面结果解释.华北地震科学,9(2):11-20.
刘昌铨,方盛明,李长法,1996.应县-淄博剖面重力、地震测深联合解释.地震地质,18(4):369-374.
刘昌铨,嘉世旭,李长法,等,1997.1966年邢台6.8级地震的深部结构背景.华北地震科学,15(2):17-23.
任青芳,张成科,赵金仁,等,1992.菏泽地区地壳结构特征与地震.华北地震科学,10(3):45-52.
王椿镛,张先康,吴庆举,等,1994.华北盆地滑脱构造的地震学证据.地球物理学报,37(5):613-619.
王家华,高海余,周叶,1999.克里金地质绘图技术———计算机的模型和算法.北京:石油工业出版社,73-77.
袁志祥,丁韫玉,狄秀玲,1999.渭河断陷及邻近地区地壳S波速度图像.地震地质,21(1):9-16.
张成科,张先康,盖玉杰,等,1997.文安-蔚县-察右中旗剖面地壳上地幔速度结构与构造研究.华北地震科学,15(3):18-28.
张建狮,祝治平,张先康,等,1997.山西高原北部地壳上地幔地震波速结构与深部构造.地震地质,19(3):220-226.
祝治平,张建狮,张成科,等,1999.山西中南部壳幔结构的研究.地震学报,21(1):42-49.
祝治平,张建狮,周雪松,等,1994.山西临汾震区地壳上地幔构造的研究.华北地震科学,12(1):77-83.
祝治平,张先康,盖玉杰,等,1995.邢台震源区及相邻地区地壳上地幔速度结构研究.地震学报,17(3):328-334.
祝治平,张先康,张建狮,等,1997.北京-怀来-丰镇剖面地壳上地幔构造与速度结构研究.地震学报,19(5):499-505.
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